Unit of Endocrinology, Dipartimento di Medicina Clinica e Chirurgia, Federico II University Medical School of Naples, Naples, Italy.
Oncological Endocrinology Unit, Department of Medical Sciences, University of Turin, AOU Città della Salute e della Scienza di Torino, Turin, Italy.
Crit Rev Food Sci Nutr. 2021;61(1):25-59. doi: 10.1080/10408398.2020.1714542. Epub 2020 Jan 30.
The incidence of differentiated thyroid cancer has been increasing in the last decades all over the world. Such a steady growth cannot be entirely attributable to more intensive thyroid nodule screening and more sensitive diagnostic procedures. Several environmental factors have changed with sufficient rapidity in the same time frame and may represent credible candidates for this increase. They include modified iodine intake, lifestyle-associated risk factors, exposure to various toxic compounds, pollutants and xenobiotics, nutritional deficiencies, eating habits and comorbidities. Foremost, nutritional patterns have gained high interest as possible promoters and modifiable risk factors for thyroid cancer in recent years. The aim of this narrative review is to focus on the relationship between thyroid cancer and nutritional factors, dietary habits and obesity. Low iodine intake has been associated to increased risk of thyroid cancer, favoring the development of more aggressive histotypes. Moreover, correction of iodine deficiency can shift thyroid cancer subtypes toward less aggressive forms, without affecting the overall risk for cancer. Actually, evidence regarding the association between selenium and vitamin D deficiency and thyroid cancer is very limited, despite their well-known anti-cancer potentials, and the clinical usefulness of their supplementation is still uncertain in this setting. Albeit the relationship between single foods and thyroid cancer is difficult to examine, fish and iodine-rich foods, vegetables, and fruits might exert protective effects on thyroid cancer risk. Conversely, no clear association has been found for other foods to date. Lastly, a clear association between obesity and the risk of thyroid cancer, with more aggressive behavior, seems to emerge from most studies, likely involving variations in thyroid function and chronic inflammation mediated by cytokines, insulin, leptin and adiponectins. Although no definite association between dietary factors and thyroid cancer has been firmly established so far, some nutritional patterns, together with excessive weight, seem to play a relevant role in thyroid cancer carcinogenesis as well as in its severity and aggressiveness. These effects may play an additive role to the well-established one exerted by environmental carcinogens, such as pollutants and radiation exposure.
在过去几十年中，全世界分化型甲状腺癌的发病率一直在上升。这种稳定的增长不能完全归因于更密集的甲状腺结节筛查和更敏感的诊断程序。在同一时间框架内，有几个环境因素发生了足够迅速的变化，它们可能是这种增长的可信候选因素。这些因素包括碘摄入量的改变、与生活方式相关的危险因素、暴露于各种有毒化合物、污染物和外源性化学物质、营养缺乏、饮食习惯和合并症。最重要的是，近年来，营养模式作为甲状腺癌的潜在促进因素和可改变的危险因素引起了高度关注。本综述的目的是重点关注甲状腺癌与营养因素、饮食习惯和肥胖之间的关系。低碘摄入与甲状腺癌风险增加有关，有利于更具侵袭性组织学类型的发展。此外，纠正碘缺乏症可以使甲状腺癌亚型向侵袭性较弱的形式转变，而不影响癌症的总体风险。实际上，尽管硒和维生素 D 缺乏与甲状腺癌之间的关联证据非常有限，但考虑到它们众所周知的抗癌潜力，在这种情况下，补充这些物质的临床实用性仍不确定。尽管单一食物与甲状腺癌之间的关系难以检测，但鱼类和富含碘的食物、蔬菜和水果可能对甲状腺癌风险具有保护作用。相反，迄今为止，没有发现其他食物与甲状腺癌之间存在明确的关联。最后，大多数研究表明，肥胖与甲状腺癌风险之间存在明确的关联，而且肥胖与更具侵袭性的行为有关，这可能与甲状腺功能的变化以及细胞因子、胰岛素、瘦素和脂联素介导的慢性炎症有关。尽管迄今为止，还没有明确确定饮食因素与甲状腺癌之间的关联，但一些营养模式，加上超重，似乎在甲状腺癌的发生以及其严重程度和侵袭性方面发挥了重要作用。这些影响可能与污染物和辐射暴露等已确立的环境致癌物的作用具有相加作用。
